Glass-Ceramic Cover Composition for Drop and Scratch Resistance
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Solution Overview
Problem
Existing protective glass for electronic devices, such as aluminosilicate glass, lacks both sufficient drop resistance and scratch resistance, leading to high breakage rates and poor user experience.
Innovation Solution
A glass-ceramic composition with specific crystalline phases, including spinel and ZrO2, and controlled molar ratios of Li2O, Na2O, and K2O, combined with chemical strengthening, to enhance mechanical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If common aluminosilicate glass is used for protective glass, then the glass can be manufactured with existing processes, but the glass has poor drop resistance and scratch resistance
Solution Approach 1:
The patent develops a glass-ceramic composite material containing spinel crystalline phase (MgAl2O4) and ZrO2 crystalline phase dispersed in a glass matrix. This composite structure combines the toughness of the glass matrix with the high hardness and strength of the crystalline phases, achieving both excellent drop resistance and scratch resistance that cannot be achieved with conventional aluminosilicate glass alone.
Solution Approach 2:
The patent optimizes specific compositional parameters including MgO content (3-10%), ZnO content (3-15%), ZrO2 content (0.1-6%), and the ratio Na2O/(MgO+ZnO) (≤0.9). These parameter changes enable the formation of spinel and ZrO2 crystalline phases during heat treatment, fundamentally transforming the material properties to achieve superior mechanical strength and hardness while maintaining optical clarity.
2Reliability
If the glass-ceramic contains high content of network modifiers (Li2O, Na2O, K2O) to improve ion exchange capability, then chemical strengthening efficiency improves, but the intrinsic structure strength may be reduced
Solution Approach 1:
The patent precisely controls the ratio (Li2O+Na2O+K2O)/(SiO2+Al2O3) to be between 0.11 and 0.30, and Na2O/(MgO+ZnO) to be ≤0.9. This balanced compositional design ensures sufficient network modifiers for effective ion exchange and chemical strengthening, while maintaining adequate network formers (SiO2, Al2O3) to preserve intrinsic structure strength and support the formation of strengthening crystalline phases.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The glass-ceramic achieves both excellent drop resistance and scratch resistance, with improved mechanical strength and optical performance, suitable for use in electronic device covers.
Implementation Method 1
Crystalline phases in the glass-ceramic are a spinel crystalline phase and a ZrO2 crystalline phase
Implementation Method 2
a compression pressure layer is formed on a surface of the glass-ceramic, and there is a tensile stress layer inside the glass-ceramic. The glass-ceramic is chemically strengthened glass-ceramic
Data Source
AI summary
A glass-ceramic and a preparation method therefor, a glass cover, and an electronic device, where crystalline phases in the glass-ceramic are a spinel crystalline phase and a ZrO2 crystalline phase. The glass-ceramic includes SiO2, Al2O3, MgO, ZnO, ZrO2, Na2O, Li2O with a molar percentage of 0% to 9%, and K2O with a molar percentage of 0% to 5%; and molar percentages of components satisfy: 0.11≤(Li2O+Na2O+K2O)/(SiO2+Al2O3)≤0.30, and Na2O/(MgO+ZnO)≤0.9.